According to the Chicago Tribune, a 23-year-old woman was sexually assaulted at a Foo Fighters show last night (July 29). After the alleged incident, the anonymous female fan reported to the nursing station, where police and an ambulance were called.

Last night was the first of two shows Foo Fighters are playing at Chicago’s Wrigley Field. According to the woman’s testimony, she was groped while waiting in line for food at the stadium. After leaving the line and walking to a port-a-potty, the man followed her and entered the port-a-potty before she could lock the door. She reports being sexually assaulted, with the alleged offender grabbing her neck and hitting her head against the wall.

The man has been described as white, between 40-50 years old, 5’9”, with thinning brown hair and possibly a receding hairline. No suspects have yet been taken into custody. Police state they’re currently processing video and that the port-a-potty has been seized as evidence. The Chicago Cubs organization is cooperating with the investigation.

“We are using every available resource to help authorities identify and apprehend the suspect and are working with CPD to address the matter quickly,” says Julian Green, Vice President of Communications and Community Affairs for the Cubs. “We are encouraging anyone who may have information to please contact police. We are increasing security staff in the portable restroom area so we have a fixed visual presence to monitor guests going in and out of the restrooms. Guest safety is paramount at Wrigley Field and we take every opportunity to ensure our guests’ safety, including routinely reviewing our security protocols and procedures with police.”

As Green stated, the Cubs organization has increased their security presence for tonight’s (July 30) Foo Fighters concert at Wrigley.